Internal Medicine Resident Western University London, Ontario, Canada
Background: Cardiovascular disease (CVD) is a leading cause of morbidity and mortality globally. Lipoprotein(a) [Lp(a)] is a significant but overlooked independent, heritable CVD risk factor. In the general population, 20% have elevated Lp(a) levels (>100 noml/dl). The Canadian practice guidelines recommend measuring Lp(a) levels once in a person’s lifetime to assess CV risk, but it is rarely done.
We aim to establish the prevalence of elevated Lp(a) in patients with or at risk of CVD participating in a virtual digital CV health program (VIRTUES) in London and Newmarket, Ontario, and to explore the significance of elevated Lp(a) in this population.
The hypotheses are (1) higher prevalence of elevated Lp(a) in this population than in the general population; compared with those with low Lp(a) ( < 100 nmol/L), (2) a higher proportion of patients with elevated Lp(a) group had a myocardial infarction (MI), (3) patients with elevated Lp(a) had their first myocardial infarction at a younger age.
METHODS AND RESULTS: Patients known or at risk of CVD were enrolled in the VIRTUES program in London and Newmarket, Ontario. A complete medical profile was captured, and a lipid profile including Lp(a) was obtained. The individuals with elevated levels of Lp(a) were identified. Multivariate analysis with traditional risk factors (diabetes mellitus, high LDL-C, hypertension, smoking, obesity) and Lp(a) levels was performed in patients with MI.
A total of 108 patients were included; 36 patients (33%) had elevated levels of Lp(a). More patients with elevated Lp(a) (18/36 (50%)) than patients with low Lp(a) (18/75(25%)) had an MI (p = 0.017). There is a trend that those with elevated Lp(a) had their first MI at a younger age (mean 54 yrs) than those with low Lp(a) (mean 60 yrs) (p = 0.103). In a logistic regression analysis accounting for traditional risk factors, elevated Lp(a) is the most important risk factor (p = 0.005), followed by male sex (p = 0.044), for having an MI.
Conclusion: Our cohort has a higher prevalence of elevated Lp(a) than the general population. A higher proportion of patients with elevated Lp(a) had an MI, and a trend of first MI at a younger age. After accounting for other traditional risk factors, Lp(a) is the most important risk factor in this patient population with an MI. As therapies for elevated Lp(a) evolve, this study demonstrates the importance of Lp(a) screening and further exploration of Lp(a) in this population.
